Presently, there is an increased demand for corn cobs as a feedstock for cellulosic ethanol, as well as other uses. As a result, there is heightened interest in collecting corn cobs during corn harvest. There is also concern by some that cob collection may reduce soil nutrient content. In this regard, crop residue or stover, e.g., corn stalks, leaves, husks and cobs, are traditionally left on the field after harvest, and break down over time to replenish soil nutrients. If a component of the stover, e.g., cobs is instead collected, nutrient levels could be lowered as a result. To mitigate this concern, some consider it desirable when collecting cobs, to collect only the cobs, that is, clean cobs with substantially all residual husks, leaves and stalks removed, and return the other stover to the field. Thus, it is sought to have a cob collection device and conveyor adapted for operation in connection with a corn harvester, which incorporates an ability to separate or clean the cobs from the other stover, including removing husks and the like attached to the cobs, and return the other stover to the field or another location. It is also desirable for the collected cobs to be as compact as possible, e.g., without attached husks and the like, so as to maximize the amount of cobs that the collection device and subsequent containers can hold. Still further, for some techniques for producing ethanol from corn cobs, the presence of other stover, e.g., husks and the like, is undesired, and for a load of cobs of a given volume, the amount of compensation paid will be reduced if significant stover is present.
Numerous apparatus have been proposed for use in connection with cob collection devices, for cleaning or separating cobs from the other stover. To illustrate, prior to the early 1960's, the common corn harvesting practice involved picking the ears of corn in the field, removing husks from the ears, and transporting the ears still containing the corn kernels to a corn crib, and later shelling the corn off of the cobs at a stationary sheller. This harvesting procedure has been almost entirely replaced by modern self-propelled combine type harvesters, which separate and collect the corn kernels, and discharge the cobs and other stover onto the field.
Combines which harvest the corn and separate the kernels from the cobs and other stover or residue, then discharge the cobs and other stover onto the field, are now the industry standard. More recently, devices for collecting cobs discharged from combines have been developed. Several of such known devices have variously utilized a towed cart or wagon for receiving and holding the cobs, and a conveyor system for conveying the cobs from the combine to the cart or wagon. Some of the cob collection devices also include apparatus for separating the cobs from the other stover or residue, mainly using air flow. Reference in this regard, Flamme U.S. Pat. No. 5,941,768, issued Aug. 24, 1999, which discloses a cob collection unit pulled behind a combine to collect on a first conveyor all the residue discharged from the combine, with a separation unit behind the conveyor including a second conveyor, and utilizing a fan to suck the stover from the cobs as they are released from the top of the second conveyor and to blow the stover back onto the field. Redekop et al. U.S. Patent Publication Nos. 20090095662 published Apr. 16, 2009; 20090104952 published Apr. 23, 2009; and 20090124309 published May 14, 2009, disclose a pulled cob collection unit, which utilizes a sequential series of inclined belt conveyors, and blower or suction fans for directing air through the discharged material as it falls from the upper end of one conveyor onto a lower end of the next conveyor, such that the heavier cobs are to continue to the next conveyor and the lighter stover or residue will be carried away by the air flow, with the cobs being conveyed into a collection tank by a further conveyor or conveyors.
Reference also Stukenholtz U.S. Pat. No. 6,358,141 issued Mar. 19, 2002, and Redekop et al. U.S. Patent Publication No. 20090137295, which disclose cob collection systems on a combine which utilize on-board bins and cob separation using sieves on the combine itself.
A shortcomings variously of the known cob collection devices and systems, is a lack of a capability for reliably removing husks and/or leaves, or fragments thereof, which still remain attached to the cobs after processing of the cobs through the systems of the combine, including gathering of the corn plants and separation of the corn ears from the stalks by the header, conveying through the feeder, agitation and separation of the kernels from the cobs by the threshing mechanism, and post-threshing handling, including in some cases passage through sieves and other systems designed for separating the cobs from the other residue or stover. Such attached husks and the like are disadvantageous as they increase the volume of the collected cobs, and reduce the ease of conveyance and compactability thereof, such that for a given volume of collected cobs, an undesirable portion of the volume can comprise the husks and the like which can have a lower energy content compared to the cobs alone, and create open spaces or interstices between the collected cobs, which factors can combine to reduce the value of a given volume of the collected cobs, as noted above.
Additionally, various of the known cob collection devices have a limited cob storage capacity or volume. In this regard, in many instances, it will be desirable to maximize the capacity of the cob collection device, within the load carrying or towing capability of the associated harvesting machine or other means of propulsion, which will typically entail maximizing the length and height dimensions of the cob collection device. For instance in this latter regard, it will typically be desirable for the height of the cob collection device to correspond to about that of the combine with which it is used. However, when a larger cob collection device is used, some manner of distributing the cobs within the device may be required, and the device should be adaptable for travel over public thoroughfares, under bridges and utility wires, and through doorways and the like.
Thus, what is sought is a cob collection device or apparatus for operation in association with a harvester, which provides one or more of the capabilities, namely, positively separating or detaching attached husks from the cobs, maximizing cob carrying capacity, and adaptability for travel over public thoroughfares, under bridges and utility wires, and through doorways and the like, and which overcomes one or more of the disadvantages, set forth above.